Observation of Fermi arcs and Weyl nodes in a noncentrosymmetric magnetic Weyl semimetal

Weyl semimetal (WSM), a novel state of quantum matter, hosts fermions as emergent quasiparticles resulting from the breaking either inversion or time-reversal symmetry. Magnetic WSMs that arise broken symmetry provide an exceptional platform to understand interplay between magnetic order and physics, but only few have been realized. Here, we identify CeAlSi new noncentrosymmetric WSM via angle-resolved photoemission spectroscopy (ARPES) first-principles, density-functional theory based calculations. Our surface-sensitive vacuum ultraviolet ARPES data confirm presence surface Fermi arcs conclusive evidence for existence semimetallic in CeAlSi. We also observe bulk cones at arc terminations using bulk-sensitive soft-x-ray measurements. These results implicate unique investigating exotic phenomena interaction topology magnetism.